The present invention pertains to a reflector system, and in particular to the construction of a reflector system having a curved front reflecting surface.
The use of large, curved projection screens has relatively recently become quite widespread in certain applications. For example, large screen projection television systems are currently being developed and sold in which the TV image is projected on a screen which is several feet in diameter. In addition, large, curved screens are being used in daytime projection systems for educational and other purposes. In both such applications, the curved screen is necessary to make proper use of high gain reflective materials, as discussed at length in the patent to Chandler, U.S. Pat. No. 3,408,132. Chandler discloses the use of a compression rolled aluminum foil as the reflective material, and other high gain reflective materials can be used as well.
A difficulty arises in mounting the high gain reflective material so that it retains its curved configuration. Generally, such reflective materials, an example of which is compression rolled aluminum foil, have no structural rigidity. The reflective material must be mounted so that the reflecting surface provided thereby is smooth and accurately conforms to the desired curved configuration, and retains its configuration indefinitely.
It has been the practice to mount the high gain reflective material so that it retains its curved configuration by applying a heavy coating of fiberglass or other structural material to the back of the reflecting material. See, e.g., a second patent to Chandler, U.S. Pat. No. 3,655,472. This layer of structural material must be quite thick to provide sufficient structural rigidity to the reflective material over its entire surface, generally constituting 20 or more square feet.
Certain of the deficiencies in known techniques for maintaining the high gain reflective material in its curved configuration are immediately evident. For example, such techniques are relatively inefficient in that they require large quantitites of raw material. Moreover, the backing material increases the weight of the screen, which is undesirable because in most applications for such a screen, it must be somewhat portable. However, perhaps the most significant difficulty with such construction techniques is that the front reflecting surface is quite often distorted while the backing is applied, decreasing the quality of the final product. To obtain an acceptable product using such production techniques exacting measures must often be taken and the construction process becomes quite expensive and time-consuming.